When launching the game or attempting to start a mission/multiplayer match, the application halts and displays a dialog box reading:

Call of Duty: Black Ops 2, developed by Treyarch and published by Activision, is a first-person shooter game that was released in 2012. The game received widespread critical acclaim for its engaging gameplay, impressive graphics, and thrilling multiplayer mode. However, some players have encountered a frustrating issue that has hindered their gaming experience: the "sound bank failed to load" error.

At its core, the "Sound Bank" error is a communication breakdown. The game engine attempts to locate and load a specific set of audio files (weapon sounds, character dialogue, ambient noise) from its "sound bank." When the game fails to find these files or finds them corrupted, it refuses to proceed. This is not a hardware issue; your speakers or headset are almost certainly fine. Instead, the problem is almost always software-related, stemming from one of three free-to-fix sources: missing system dependencies, corrupted game files, or the game’s notoriously poor handling of default Windows audio devices.